The connector bases currently in use under such conditions are passive bases, i.e. they do not include an opto-electronic component.
The front portion of a passive base mounted on a panel of an electronic apparatus receives a plug; the rear portion is connected inside the electronic apparatus to one or two optical fibers with each optical fiber being devoted to a particular direction of transmission. Each fiber has an optical plug at its other end for connection to an active (transmission or reception) base, which base is equipped with a light-emitting diode if it is a transmission base or with a light-receiving diode if it is a receiving base. Such active bases are, naturally, fixed on or close to an electronic circuit, e.g. a printed circuit card, with the light-emitting or light-receiving diode being connected to said electronic circuit.
This type of connection suffers from several drawbacks:
a connection between two electronic circuits belonging to two different apparatuses has several coupling points; PA1 if a light-emitting or light-receiving diode fails, the base fitted with the faulty diode must be replaced in the corresponding apparatus since the diode itself is not dismountable; and PA1 the presence of optical fibers between a passive base and the electronic circuits within an electronic apparatus can give rise to problems of space occupation, in particular for receiving optical fibers which have relatively large minimum possible radiuses of curvature and which must be provided with a certain amount of spare length; the reliability of the apparatuses and thus of a connection, and the lifetime of optical fibers in a apparatus are thus compromised when the available space is limited, even though the apparatus is not as compact as it could be if it had no optical fibers. PA1 said cylindrical support is a hollow support having a bottom with a hole whose diameter is greater than the diameter of the package whose flange is pressed against said bottom inside the support, PA1 the support and the package constitute an assembly received inside the socket, PA1 said hole through the hollow support allows the package to be moved perpendicularly to the axis XX' of the socket in order to position the diode on said axis XX', and PA1 after the diode has been positioned, the package is kept in position by retention means inserted in the support, said diode positioning being performed during manufacture of the optical module.
French Pat. No. 2 440 009 describes a base and a receiving end-fitting body equipped with a photodiode, said receiving end-fitting being fixed on one end of the base by two screws which pass through two holes provided in the body of the receiving end-fitting with considerable play, the base including two tapped holes for receiving said screws. The base receives a plug provided with an end-fitting having the end of an optical fiber fixed at the end of the fitting, and the receiving end-fitting body is moved until the best possible transmission is obtained between the optical fiber and the photodiode window, after which said screws are tightened in order to lock the receiving end-fitting in said position.
With this type of base, replacing a defective photodiode requires the base to be disassembled together with the receiving end-fitting; for example, if the defective receiving end fitting is replaced by a new receiving end-fitting, the new receiving end-fitting needs to be positioned and such positioning is generally performed by micromanipulation, which is practically impossible to perform on-site, since a user does not normally have the necessary equipment. It is therefore necessary to provide the base assembly with a spare receiving end-fitting, thereby avoiding the positioning problem but nevertheless requiring the faulty receiving end-fitting base assembly to be disassembled and the spare assembly to be assembled.
Preferred embodiments of the present invention remedy the drawbacks of currently used connectors, and in particular reduce the number of coupling points in an optical link, avoid having optical fibers in an apparatus so as to reduce the space it occupies, and enable faulty light-emitting or light-receiving diodes to be easily replaced.